Search for dissertations about: "finite elements"

Showing result 21 - 25 of 320 swedish dissertations containing the words finite elements.

  2. 21. Adaptive finite element methods for multiphysics problems

    Author : Fredrik Bengzon; Mats Larson; Harald van Brummelen; Umeå universitet; []
    Keywords : finite element methods; multiphysics; a posteriori error estimation; duality; adaptivity; discontinuous Galerkin; fractional step methods;

    Abstract : In this thesis we develop and analyze the performance ofadaptive finite element methods for multiphysics problems. Inparticular, we propose a methodology for deriving computable errorestimates when solving unidirectionally coupled multiphysics problemsusing segregated finite element solvers. READ MORE

  4. 22. Postprocessing Techniques and Adaptivity in the Finite Element Method

    Author : Fethi Abdulwahab; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; error estimation; postprocessing; adaptivity; superconvergence; finite element;

    Abstract : The Finite Element (FE) method is an approximate method and as such the accuracy of its solutions must be controlled to allow for a reliable application. This thesis deals with error estimation and improvements of the FE solutions based on superconvergent properties of the FE solution in certain points. READ MORE

  5. 23. Elastohydrodynamically lubricated finite line contacts operating under transient conditions

    Author : Tobias Hultqvist; Roland Larsson; Lars-Erik Stacke; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

    Abstract : The effect of greenhouse gas emissions contributing to the global warming is today becoming an increasingly important problem worldwide and has led to increased efforts being made on improving tribological performance of interacting surfaces in mechanical systems. Due to increasingly stringent CO2regulations, a reduced fuel consumption has become a key area of interest for the automotive industry where low cost, low emission solutions are continuously developed and where low friction alternatives to machine elements currently in use are evaluated. READ MORE

  6. 24. Nonlinear dynamics of flexible structures using corotational beam elements

    Author : Thanh-Nam Le; Jean-Marc Battini; Reijo Kouhia; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; corotational method; nonlinear dynamics; large displacements; finite rotations; time stepping method; thin-walled cross-section; beam element;

    Abstract : The purpose of this thesis is to develop corotational beam elements for the nonlinear dynamic analyse of flexible beam structures. Whereas corotational beam elements in statics are well documented, the derivation of a corotational dynamic formulation is still an issue. READ MORE

  7. 25. Towards higher order immersed finite elements for the wave equation

    Author : Simon Sticko; Gunilla Kreiss; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : We consider solving the scalar wave equation using immersed finite elements. Such a method might be useful, for instance, in scattering problems when the geometry of the domain is not known a priori. For hyperbolic problems, the amount of computational work per dispersion error is generally lower when using higher order methods. READ MORE